In this scene from book 6 (Harry Potter and the Half-Blood Prince) Harry looks for a place in the Room of Requirement to hide his potions books.

About this creation

There are lots of things that are supposed to be in there (books, bird in a cage from the movie, the vanishing cabinet, Ravenclaw's diadem). There are also some nods to other fandoms in here (a lightsaber, a TARDIS, etc.)